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प्रश्न
A person cannot see distant objects clearly. His vision can be corrected by using the spectacles containing:
(a) concave lenses
(b) plane lenses
(c) contact lenses
(d) convex lenses
उत्तर
concave lenses
Concave lenses are used to correct the defect of vision and enable the person to see distant objects clearly.
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संबंधित प्रश्न
Where must the object be placed for the image formed by a converging lens to be:
real, inverted and larger than the object?
Draw a diagram to show how a converging lens focusses parallel rays of light?
Take down this figure into your answer book and complete the path of the ray.
Which type of lens is
a diverging lens? Explain your answer with diagrams.
When sunlight is concentrated on a piece of paper by a spherical mirror or lens, then a hole can be burnt in it. For doing this, the paper must be placed at he focus of:
(a) either a convex mirror or convex lens
(b) either a concave mirror or concave lens
(c) either a concave mirror or convex lens
(d) either a convex mirror or concave lens
An object 60 cm from a lens gives a virtual image at a distance of 20 cm in front of the lens. What is the focal length of the lens? Is the lens converging or diverging? Give reasons for your answer.
A concave lens has focal length 15 cm. At what distance should the object from the lens be placed so that it forms an image at 10 cm from the lens? Also find the magnification produced by the lens.
State whether the following statement is true or false:
Short-sightedness can be cured by using a concave lens.
A lens forms an upright and diminished image of an object irrespective of its position. What kind of lens is this?
